Electrified vehicles, including Battery-electric (BEV), Plug-in Hybrid Electric (PHEV) and traditional Hybrid Electric (HEV), employ a high-voltage traction battery to store energy. The traction battery is composed of multiple battery cells in at least one series string, such that the traction battery voltage is the sum of the voltages of the cells in series. In some cases, some cells of the battery may be charged to a greater voltage level than other cells. As the traction battery may be charged from a current source connected to the at least one series string, the charge level of the battery may be limited by the charge level of the most charged cells to avoid overcharging.